The 'name_space' name space URI is a duplicate.
Explanation
The namespace URI for a schema package must be unique. In wimextension.xsd, the namespace URI is defined using targetNamespace. In wimxmlextension.xml, the namespace URI is defined through attribute nsURI.
User response
Ensure that the namespace URIs that are defined in both wimextension.xsd and wimxmlextension.xml file do not conflict with each other.